From: Michael Schmitz <schmitzmic@gmail.com>
To: linux-m68k@vger.kernel.org, geert@linux-m68k.org
Cc: ebiederm@xmission.com, viro@zeniv.linux.org.uk,
Michael Schmitz <schmitzmic@gmail.com>
Subject: [PATCH v8 2/3] m68k/kernel - check syscall_trace_enter() return code on m68k
Date: Thu, 13 Jan 2022 14:09:02 +1300 [thread overview]
Message-ID: <20220113010903.720-3-schmitzmic@gmail.com> (raw)
In-Reply-To: <20220113010903.720-1-schmitzmic@gmail.com>
Check return code of syscall_trace_enter(), and skip syscall
if -1. Return code will be left at what had been set by
ptrace or seccomp (in regs->d0).
No regression seen in testing with strace on ARAnyM.
Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
--
Changes from v7:
Al Viro:
- split return code checks from switch to syscall_trace_enter()
Changes from v6:
Geert Uytterhoeven:
- add syscall_trace_enter() return code check for 68000
and coldfire
Changes from v5:
- add comment to explain optimization
Changes from v4:
Andreas Schwab:
- optimize return code test (addql #1,%d0 for cmpil #-1,%d0)
- spelling fix in commit message
Changes from v3:
- change syscall_trace_enter return code test from !=0 to ==-1
---
arch/m68k/68000/entry.S | 2 ++
arch/m68k/coldfire/entry.S | 2 ++
arch/m68k/kernel/entry.S | 2 ++
3 files changed, 6 insertions(+)
diff --git a/arch/m68k/68000/entry.S b/arch/m68k/68000/entry.S
index 997b54933015..7d63e2f1555a 100644
--- a/arch/m68k/68000/entry.S
+++ b/arch/m68k/68000/entry.S
@@ -45,6 +45,8 @@ do_trace:
jbsr syscall_trace_enter
RESTORE_SWITCH_STACK
addql #4,%sp
+ addql #1,%d0
+ jeq ret_from_exception
movel %sp@(PT_OFF_ORIG_D0),%d1
movel #-ENOSYS,%d0
cmpl #NR_syscalls,%d1
diff --git a/arch/m68k/coldfire/entry.S b/arch/m68k/coldfire/entry.S
index 9f337c70243a..35104c5417ff 100644
--- a/arch/m68k/coldfire/entry.S
+++ b/arch/m68k/coldfire/entry.S
@@ -90,6 +90,8 @@ ENTRY(system_call)
jbsr syscall_trace_enter
RESTORE_SWITCH_STACK
addql #4,%sp
+ addql #1,%d0
+ jeq ret_from_exception
movel %d3,%a0
jbsr %a0@
movel %d0,%sp@(PT_OFF_D0) /* save the return value */
diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S
index 18f278bdbd21..0d5b7085d76f 100644
--- a/arch/m68k/kernel/entry.S
+++ b/arch/m68k/kernel/entry.S
@@ -184,6 +184,8 @@ do_trace_entry:
jbsr syscall_trace_enter
RESTORE_SWITCH_STACK
addql #4,%sp
+ addql #1,%d0 | optimization for cmpil #-1,%d0
+ jeq ret_from_syscall
movel %sp@(PT_OFF_ORIG_D0),%d0
cmpl #NR_syscalls,%d0
jcs syscall
--
2.17.1
next prev parent reply other threads:[~2022-01-13 1:09 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-13 1:09 [PATCH v8 0/3] Add kernel seccomp support for m68k Michael Schmitz
2022-01-13 1:09 ` [PATCH v8 1/3] m68k/kernel - wire up syscall_trace_enter/leave " Michael Schmitz
2022-01-13 1:09 ` Michael Schmitz [this message]
2022-01-13 1:09 ` [PATCH v8 3/3] m68k: add kernel seccomp support Michael Schmitz
2022-01-14 22:51 ` [PATCH v8 0/3] Add kernel seccomp support for m68k John Paul Adrian Glaubitz
2022-01-17 20:49 ` Michael Schmitz
2022-01-17 18:06 ` Eric W. Biederman
2022-01-17 20:47 ` Michael Schmitz
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